Modelling cell division in blender
Here may be an alternative to Metaballs, I remember seeing something similar done with 3DS Maxs symmetry modifier so I attempted to try something with Blenders mirror modifier in combination with other modifiers.





On your mesh that you want to split go into edit mode and select some vertices where you want there to be tension during the animation and apply a hook modifier then a mirror modifier (use a empty for your mirror modifier origin) and then apply some smooth and sub D modifiers towards the end. Maybe the animation can be baked and then soft body dynamics could be applied but I've never tried that though, just a thought.